This invention relates to apparatus for cutting trees, and more particularly, to apparatus wherein shear members are moved into engagement with a tree to cut the tree.
In recent years, a number of structures have been developed wherein shear members are brought together to cut a tree adjacent its base, with the body of the tree being held by gripping members during such operation. In general, it will be understood that such structures should be capable of not only effectively cutting the tree, for example, through the proper application of force by force-applying means to the shear members, but also with advantage should be compact in design and capable of dealing properly with the extremely high forces placed thereon during the cutting operation.
U.S. Pat. No. 3,575,222 discloses a system generally along the above-stated lines. It should be noted, however, that such system utilizes a single cylinder for applying force through linkages to shear members. Similarly U.S. Pat. No. 3,837,382 utilizes a single cylinder as the means for applying force to a single shear member to cut the tree. And, U.S. Pat. No. 3,540,501 discloses a pair of cylinders for operating shear members, but with no linkage means actuated by the cylinders and with which the cylinders and shear members cooperate.